Monitoring system for paving machine conveyor system

ABSTRACT

A monitoring system for a paving machine having a conveyor system is disclosed. The monitoring system may include an input device configured to receive a first input indicative of a paving material efficiency factor, and a first sensor configured to generate a first signal indicative of a conveyor speed. The monitoring system may further include a controller electronically connected to the input device and the first and configured to determine an amount of material deposited by the paving machine based on the paving material efficiency factor and the conveyor speed.

TECHNICAL FIELD

The present disclosure relates generally to a monitoring system and, more particularly, to a monitoring system for a paving machine conveyor system.

BACKGROUND

Paving machines are used to deposit layers of asphalt onto a roadway or parking lot bed. A paving machine generally includes a hopper that receives heated asphalt, a screed, and a conveyor system that moves the heated asphalt from the hopper onto the bed in front of the screed. The screed is pushed or pulled over the asphalt to level and shape the asphalt into a layer of paving material having a desired thickness and width. In some applications, the paving machine is connected to and towed by a dump truck supplying the asphalt to the hopper. In other applications, the paving machine includes a tractor that self-powers the paving machine.

The amount of paving material deposited by the paving machine is a function of multiple factors, including the speed of the paving machine, the speed of the conveyor, and how much material remains in the hopper. During a paving operation, it can be difficult to determine whether the proper amount of asphalt is being applied to the bed and whether any of these factors should be adjusted until at least a significant portion of the bed has been covered with asphalt. This determination can be made more complicated when the desired thickness and/or width of the layer is varied by the paving crew throughout the paving operation in accordance with the customer's specifications. As a result, portions of the bed may receive too much asphalt and incur a greater operational cost than anticipated. In other situations, too little asphalt may be deposited and a penalty for failing to meet the customer's specifications may be incurred.

One attempt to monitor the amount of material deposited by a paving machine is disclosed in U.S. Pat. No. 8,930,092 B2 of Minich that issued on Jan. 6, 2015 (“the '092 patent”). Specifically, the '092 patent discloses an asphalt paver having a hopper for storing asphalt, a tractor drive system for transporting the hopper, and a variable-width screed attached to the tractor drive system. A conveyor transports asphalt from the hopper to the front of the screed via a tunnel, where an auger disperses the asphalt along the width of the screed. The width of the screed is sensed by width sensors attached to left and right sides of the screed. Material height sensors disposed within the tunnel measure the height of the material as it travels from the hopper to the screed, and motion detection devices measure the linear speed of the conveyor. Using a calibration curve, a computer system determines an incremental weight of asphalt being laid down by the paver based on the screed width, material height, and conveyor speed. Using the paver speed (as determined by a speed sensor), the computer system determines an instantaneous amount of paving material or “yield” being applied during the paving process as well as a total yield over period of paving time. The total yield is compared to an actual or “ticket” amount of asphalt delivered by a truck to determine whether all of the delivered asphalt was consumed by the paver.

Although the paver of the '092 patent may allow paver yield to be monitored, it may not be optimum. In particular, the paver of the '092 patent may be too complex and costly as it uses material height sensors in conjunction with screed width sensors to determine how much material has been deposited. Further, the calibration curve used to determine the weight of material may not be universally applicable to various types of paving materials having different properties, which may lead to inaccurate weight and material deposition determinations.

The disclosed monitoring system are directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.

SUMMARY

In one aspect, the present disclosure is directed to a monitoring system for a paving machine having a conveyor system. The monitoring system may include an input device configured to receive a first input indicative of a paving material efficiency factor, and a first sensor configured to generate a first signal indicative of a conveyor speed. The monitoring system may further include a controller electronically connected to the input device and the first sensor and configured to determine an amount of material deposited by the paving machine based on the paving material efficiency factor and the conveyor speed.

In another aspect, the present disclosure is directed to a method of monitoring a paving machine having a conveyor system. The method may include conveyor paving material through a tunnel associated with the conveyor system, receiving a first input indicative of a paving material efficiency factor, receiving a first signal indicative of a conveyor speed, and determining an amount of material deposited by the paving machine based on the paving material efficiency factor and the conveyor speed.

In yet another aspect, the present disclosure is directed to paving machine. The paving machine may include a machine frame, a plurality of traction devices configured to support the machine frame, and an engine mounted to the machine frame and configured to drive the plurality of traction devices. The paving machine may further include a hopper mounted at a first end of the machine frame, a conveyor system configured to transport material from the hopper to a second end of the machine frame via a tunnel associated with the conveyor system, a screed mounted at the second end of the machine frame, and a monitoring system associated with the conveyor system. The monitoring system may include an input device configured to receive a first input indicative of a paving material efficiency factor, a first sensor configured to generate a first signal indicative of a conveyor speed, a second sensor configured to generate a second signal indicative of a fill level of the tunnel, and a controller electronically connected to the input device and the first and second sensors and configured to determine an amount of material deposited by the paving machine based on the paving material efficiency factor, the conveyor speed, and the fill level of the tunnel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side-view illustration of an exemplary disclosed paving machine;

FIGS. 2 and 3 are end-views of a conveyor assembly that may be used in conjunction with the paving machine of FIG. 1; and

FIG. 4 is a diagrammatic illustration of an exemplary disclosed monitoring system that may be used in conjunction with the paving machine of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary paving machine 10 having a tractor portion 12 carrying a front-mounted hopper 14 and towing a screed assembly 16. A conveyor system 18 having belts, chains, and/or augers may be situated to transport paving material (e.g., a hot asphalt mixture) from hopper 14 to screed assembly 16. Screed assembly 16 may then level and shape the material into a layer having a desired thickness and width on top of a work surface 17. In the disclosed example, paving machine 10 is self-powered by way of tractor portion 12. It is contemplated, however, that tractor portion 12 may alternatively be omitted, and hopper 14 and/or screed assembly 16 towed by another machine (e.g., a dump truck), if desired.

Tractor portion 12 may include, among other things, a machine frame 20, a plurality of traction devices 22 (e.g., tracks or wheels—only one shown in FIG. 1) configured to support machine frame 20, a power source (e.g., an engine) 24 configured to drive traction devices 22, and an operator station 26 configured to provide operator control over paving machine 10. Machine frame 20 may support hopper 14, and transmit tractive forces to screed assembly 16 (e.g., by way of tow arms 28—only one shown in FIG. 1). One or more actuators 30 may be connected between machine frame 20 and tow arms 28, and controlled (e.g., for example via operator station 26) to raise, lower, shift, and/or tilt screed assembly 16 relative to machine frame 20. It is also contemplated that screed assembly 16 may generally be free floating, if desired, and only raised or lowered for roading or paving operations, respectively.

As shown in FIG. 2, conveyor system 18 may include one or more conveyors 32, each disposed in a tunnel 34 and driven by a drive system 36. Material from hopper 14 (referring to FIG. 1) may be fed into tunnel 34, and drive system 36 may be selectively operated to convey the material to screed assembly 16 via one or more of conveyors 32. In the example of FIG. 2, conveyor system includes a left side 38 and a right side 40, each including a respective conveyor 32 and tunnel 34. It is understood, however, that conveyor system 18 may include more or fewer conveyors and tunnels, if desired. A fill level sensor (“sensor”) 42 may be associated with each of left and right sides 38, 40 of conveyor system 18 and configured to generate a signal indicative of a fill level 4) of tunnel 34 (i.e., how full tunnel 34 is with material from hopper 14). A conveyor speed sensor (“sensor”) 44 (shown only in FIG. 4) may also be associated with each conveyor 32 and configured to generate a signal indicative of a linear speed s₁ of the respective conveyor 32.

Conveyors 32 may be a flexible component configured to support paving material on its surface and be driven by drive system 36. For example, conveyor 32 may include a plurality of links 46 connected around drive system 36 to form a chain or a linked belt. Links 46 may travel around drive system 36 on a number of sprockets and or in conjunction with a drive chain 48. In other embodiments conveyor 32 may include an endless belt that is held in tension and travels around a number of pulleys. Other configurations of conveyor 32 may be used.

Tunnel 34 may be a partially enclosed passage extending from a first end of machine frame 20 (referring to FIG. 1) to an opposite second end of machine frame 20 for the conveyance of material from hopper 14 to screed assembly 16 via conveyor 32. Tunnel 34 may be positioned between traction devices 22 and include one or more components configured to guide material along a length of machine frame 20. For example, a bottom side of tunnel 34 may be defined by conveyor 32, and lateral sides may be defined by one or more walls 50. Material exiting tunnel 34 may be deposited on work surface 17 and formed into a layer of pavement having a desired width and thickness by screed assembly 16.

As shown in FIG. 3, tunnel 34 may have a cross-sectional area (“area”) A_(T) partially defined by conveyor 32 and walls 50. As paving material is conveyed from hopper 14 to screed assembly 16, the material may be shaped by walls 50 such that the material attains the same shape and/or cross-section as tunnel 34. That is, the orientation of walls 50 may influence the shape and/or cross-section of the material being conveyed from hopper 14 to screed assembly 16. For example, FIG. 3 shows walls 50 having an angled orientation, resulting in a trapezoid-like cross-section of tunnel 34. Material transported via conveyor 32 may be shaped by walls 50 to attain the same trapezoid-like cross section. In other embodiments, walls 50 may not be angled (e.g., may be vertical) and/or tunnel 34 may have a different shape of cross-section (e.g., rectangular, oval, etc.). Tunnel 34 may be full when material transported via conveyor 32 reaches the top of walls 50. As hopper 14 is gradually emptied, the material in hopper 14 may fall to a level below the top of walls 50 and tunnel 34 may no longer be full. In these situations, the cross-sectional area of material on conveyor 32 may be reduced to a fraction or percentage of the area A_(T) of tunnel 34.

Referring again to FIG. 2, drive system 36 may include one or more rollers 52 configured to support conveyor 32. One or more sprockets 54 and/or pulleys may be supported on the ends of rollers 52 or on separate shafts and configured to engage elements of conveyor 32 for transferring tractive forces to conveyor 32. At least one driving element, such as a motor (not shown in FIG. 2), may be connected to sprockets 54 via a shaft, chain, belt, etc., in order to provide tractive forces for driving conveyor 32. The motor may be an electric motor, a hydraulic motor, or another type of motor, if desired.

Sensor 42 may be positioned near conveyor 32 and configured to generate a signal indicative of the fill level Φ of tunnel 34. The fill level Φ may be a factor indicative of an extent to which tunnel 34 is filled with material from hopper 14. Sensor 42 may be positioned near the exit of tunnel 34 in order to allow sensor 42 to detect the fill level Φ just before material on conveyor 32 is deposited in front of screed assembly 16. Sensor 42 may include a paddle 56 or another type of probe configured to engage the material within tunnel 34. Paddle 56 may be rotatably connected to a body 58 that houses signal generation components that generate a signal in response to rotational movement of paddle 56 as the fill level Φ within tunnel 34 changes.

When tunnel 34 is full (e.g., when a maximum amount of material is on conveyor 32), paddle 56 may rotate (e.g., in an upward direction) to a maximum position, causing the components within body 58 to generate a signal indicative of a higher fill level Φ (e.g., a maximum fill level). Conversely, when tunnel 34 is not full (e.g., when less than the maximum amount of material is on conveyor 32), such as when a level of material in hopper 14 has been reduced below a threshold level, the components within body 58 may generate a signal indicative of a lower fill level Φ. In one example, the fill level may be a numeric factor (e.g., 0≦Φ≦1) or a percent (e.g., 0-100%). Other ways of representing the fill level Φ may be used.

Sensor 42 may be resistive-type sensor, such as a potentiometer, that generates a variable electrical signal as paddle 56 is rotated. The signal generated by sensor 42 may be calibrated or otherwise processed with respect to the area A_(T) of tunnel 34. For example, the position of sensor 42 when tunnel 34 is full of paving material may be associated with a maximum signal value, indicating that the material in tunnel 34 shares a maximum dimension with tunnel 34 (e.g. a maximum height). Conversely, the position of sensor 42 when tunnel 34 is less than full (e.g., partially empty, fully empty, etc.) may be associated with a decreased signal value, indicating that the material in tunnel 34 has a dimension (e.g., a height) that is less than the maximum dimension of tunnel 34. The maximum signal value may be associated with the full area A_(T) of tunnel 34 as well as a maximum fill level value Q (e.g., 1, 100%, etc.). Lesser signal values may be proportionately or otherwise associated with a portion of the full area A_(T) and a corresponding lesser fill level (4 (e.g., 0.00-0.99, 0-99%, etc.). In this way, an area A_(M) (e.g., a cross-sectional area) of material in tunnel 34 may be determined by multiplying the known area A_(T) of tunnel 34 by the fill level 4 (as indicated by the signal generated by sensor 42). In other embodiments, sensor 42 may be a an optical sensor, an ultrasonic sensor, a laser sensor, or different type of sensor configured to generate a signal indicative of a dimension or other measurement (e.g., height, width, area, etc.) of the material in tunnel 34.

Sensor 44 (referring to FIG. 4) may be associated with at least one component of conveyor system 18 and configured to generate a signal indicative of the speed s₁ of conveyor 32. For example, sensor 44 may be associated with rollers 52 (referring to FIG. 2), sprockets 54, and/or the motor of drive system 36. Sensor 44 may be associated with other components, if desired. In some embodiments, sensor 44 may be a magnetic pickup sensor configured to create a pulsating signal in response to movements of a shaft or other part the associated component. In other embodiments, sensor 44 may be an optical sensor, a mechanical sensor (e.g., tachometer), or another type of sensor. Sensor 44 may alternatively be configured to determine the speed s₁ of conveyor 32 based on a power input to the motor or other driving mechanism of drive system 36. For example, sensor 44 may be configured to sense an electrical power input (e.g., via one or more of voltage, current, resistance, etc.), a hydraulic power input (e.g., via a pressure sensor), or another type of power input. The power input to the driving mechanism may be used to determine the speed of conveyor 32.

As shown in FIG. 4, a monitoring system 60 may be associated with paving machine 10 (referring to FIG. 1) and include elements that cooperate to determine and track an amount of paving material deposited by paving machine 10 onto work surface 17 (referring to FIG. 1). Elements of monitoring system 60 may include sensors 42-44, an interface device 62, a groundspeed sensor 64, a communication device 66, and a controller 68 electronically connected to each of the other components. Using information from sensors 42-44, interface device 62, and/or communication device 66, controller 68 may be configured to determine the fill level Φ of tunnel 34 and the amount of material deposited onto work surface 17. Based on the amount of material deposited and information from interface device 62, groundspeed sensor 64, and/or communication device 66, controller 68 may be configured to determine a correction factor Δ for more accurately determining subsequent amounts of material deposited on work surface 17.

In the disclosed example, interface device 62 may include, among other things, a display 70 and an input device 72. Interface device 62 may be an operator interface located in operator station 26 (referring to FIG. 1) or at another location on paving machine 10. In other embodiments, interface device 62 may be offboard paving machine 10. For example, interface device 62 may embody a remote control, such as a handheld controller, that an operator may use to control paving machine 10 from anywhere on the worksite. Interface device 62 may alternatively embody a software program and user interface for a computer, and may include a combination of hardware and software. In other embodiments, paving machine 10 may be autonomous and may not include interface device 62.

Display 70 may be configured to render the location of paving machine 10 relative to features of work surface 17 (e.g., paved and/or unpaved parts of work surface 17), and to display data and/or other information to the operator. Input device 72 may be configured to receive one or more inputs, data, and/or instructions from the operator of paving machine 10. For example, input device 72 may be an analog input device that receives control instructions via one or more buttons, switches, dials, levers, etc. Input device 72 may also or alternatively include digital components, such as one or more soft keys, touch screens, and/or visual displays. Other interface devices (e.g., control devices) may also be possible, and one or more of the interface devices described above could be combined into a single interface device, if desired.

Groundspeed sensor 64 may be associated with one or more traction devices 22, and may be configured to generate a signal indicative of a groundspeed of paving machine 10. For example, groundspeed sensor 64 may be a magnetic pickup-type sensor in communication with a magnet embedded within a rotational component of traction device 22. Groundspeed sensor 64 may alternatively be associated with a different component of paving machine 10 (e.g., a driveshaft, a transmission, flywheel, etc.), or embody a different type of sensor. In other embodiments, groundspeed sensor 64 may be a GPS device, Doppler device, or other type of position detecting device capable of generating a signal indicative of the ground speed and/or a distance traveled by paving machine 10.

Communication device 66 may include hardware and/or software that enables sending and receiving of data messages between controller 68 and an offboard entity (e.g., a haul truck, a back office computer, a computer network, a paving material plant, etc.). The data messages may be sent and received via a direct data link and/or a wireless communication link, as desired. The direct data link may include an Ethernet connection, a connected area network (CAN), or another data link known in the art. The wireless communications may include satellite, cellular, infrared, WiFi. Bluetooth, and/or any other type of wireless communications that enables communication device 66 to exchange information between paving machine 10 and the offboard entity.

Controller 68 may embody a single microprocessor or multiple microprocessors that include a means for monitoring operator and sensory inputs, and determining the amount of paving material deposited onto work surface 17 by paving machine 10 based on the inputs. For example, controller 68 may include a memory, a secondary storage device, a clock, and a processor, such as a central processing unit or any other means for accomplishing a task consistent with the present disclosure. Numerous commercially available microprocessors can be configured to perform the functions of controller 68. It should be appreciated that controller 68 could readily embody a general machine controller capable of controlling numerous other machine functions. Various other known circuits may be associated with controller 68, including signal-conditioning circuitry, communication circuitry, and other appropriate circuitry. Controller 68 may be further communicatively coupled with an external computer system, instead of or in addition to including a computer system, as desired.

Controller 68 may be configured to determine a calculated amount of material M₁ deposited by paving machine 10 onto work surface 17 based on one or more signals from sensors 42-44 and 64, input device 72 and/or communication device 66. For example, controller 68 may be configured to receive a first input indicative of a paving material efficiency factor (“material efficiency factor”) γ via input device 72 and/or communication device 66. The material efficiency factor γ may be received from the operator of paving machine 10 via manual entry using input device 72, or it may be received automatically from an offboard entity (e.g., a plant, a haul vehicle, etc.).

The material efficiency factor γ may be a numeric value indicative of a difference between a speed s₂ at which the paving material travels through tunnel 34 and the conveyor speed s₁. In some situations, different types of paving materials may each have different mechanical properties that can result in differing frictional relationships between the paving material and conveyor 32 that can lead to a relative speed difference between the paving material in tunnel 34 and conveyor 32. For example, materials having a lower coefficient of friction with respect to conveyor 32 may tend to shear or slip on the surface of conveyor 32, resulting in a difference between the conveyor speed s₁ and the speed s₂ of the paving material as it travels from hopper 14 to screed assembly 16. This slippage can cause the speed s₂ of the paving material though tunnel 34 to be less than the conveyor speed s₁.

The material efficiency factor γ of each type of paving material may be determined empirically, using modeling techniques, or by another method. For example, an amount of paving material having a known weight and/or cross-sectional area may be loaded onto a conveyor and transferred at a known conveyor speed. After a period of conveying time t, an actual amount of transferred material may be measured (e.g., weighed and/or measured) and compared to a theoretical amount of transferred material (e.g., the known cross-sectional area multiplied by the conveyor speed and conveying time t). The actual amount of transferred material may, for example, be divided by the theoretical amount to determine the material efficiency factor γ, which may be correlated to the conveyor speed. This process may be performed for a number of conveyor speeds and repeated several times at each speed to increase the accuracy of the correlation. Other ways of determining the material efficiency factor γ may be used.

By multiplying the conveyor speed s₁ by the material efficiency factor γ, for example, controller 68 may be configured to determine the speed s₂ of the paving material traveling through tunnel 34 based on the conveyor speed s₁. In this way, the actual amount of material being deposited in front of screed assembly 16 may be more accurately determined based on readily available information from existing sensors (e.g., the conveyor speed s₁) and the material efficiency factor γ, thereby obviating the need for additional sensors that can increase the complexity of monitoring system 60 and/or the cost of paving machine 10.

The conveying time t may be indicative of an amount of time that conveyor 32 is moving with a particular conveyor speed s₁. The conveying time t may be determined at a desired sampling rate and associated with the conveyor speed s₁ whenever sensor 44 generates a signal indicative of a non-zero conveyor speed s₁. In this way, when conveyor 32 is not moving, the conveying time t may have a zero value. Alternatively, the conveying time t may be determined continuously (i.e., even when conveyor 32 is not moving) and associated with the current conveyor speed s₁ according to the desired sampling rate. In this way, the conveying time t may be associated with a conveyor speed s₁ having a zero value whenever conveyor 32 is not moving.

Controller 68 may also be configured receive a second input indicative of a density ρ of the material delivered to paving machine 10. For example, controller 68 may receive the second input manually from the operator via input device 72 and/or automatically via communication device 66. The material delivered to paving machine 10 may be the same type of material deposited onto work surface 17. Thus, the density ρ of the material delivered to paving machine 10 may be equal to the density ρ of the material deposited onto work surface 17. Controller 68 may store the density ρ of the paving material in its memory for further processing.

Controller 68 may be configured to determine the calculated amount of material M₁ (e.g., a volume, a weight, etc.) deposited onto work surface 17 by paving machine 10 based on one or more of the conveyor speed s₁, the material efficiency factor γ, the fill level Φ, the tunnel area A_(T), and the density ρ of the paving material. For example, controller 68 may determine the calculated amount of material M₁ based on EQ1 below. Controller 68 may store EQ1 within its memory and access it each time M₁ is determined. Other equations, algorithms, models, etc., may be used to determine M₁.

M ₁=[(s ₁)×(γ)]×[(Φ)×(A _(T))]×ρ×t  EQ1:

By multiplying s₁, γ, Φ, A_(T), and t together, controller 68 may determine an instantaneous volumetric rate of material deposition {dot over (V)} onto work surface 17. Controller 68 may continually determine the instantaneous volumetric rate of material deposition {dot over (V)} and multiply it by an amount of paving time to determine a volume V of material deposited onto work surface 17. By summing the volume V of deposited material over a period of paving time (e.g., a shift, a day, for time spent on a particular jobsite, etc.), controller 68 may be configured to determine a total volume V_(total) of deposited material. Controller 68 may be configured to show the instantaneous volumetric rate of material deposition {dot over (V)} (e.g., cubic meters/hour, cubic yards/hour, etc.) and/or the total volume V_(total), (e.g., cubic meters, cubic yards, etc.) of deposited material to the operator of paving machine 10 via display 70.

By multiplying the instantaneous volumetric rate of material deposition {dot over (V)} and/or the total volume V_(total) of deposited material by the density ρ of the material delivered to paving machine 10, controller 68 may be configured to determine an instantaneous rate of material deposition by weight {dot over (W)} and/or a total weight W_(total), of deposited material, respectively. Controller 68 may be configured to show the instantaneous rate of material deposition by weight {dot over (W)} (e.g., tonnes/hour) and/or the total weight W_(total) (e.g., tonnes) of deposited material to the operator of paving machine 10 via display 70.

The amount of material M₁ deposited by paving machine 10 may be equal to the total weight W_(total) of deposited material, the total volume V_(total), or another amount of material deposited onto work surface 17, as desired. M₁ may represent an amount of material consumed during the paving process that may be comparable to a known amount of material delivered to paving machine 10. For example, when an amount of material M₂ delivered to paving machine 10 is provided as a weight value (e.g., in tonnes), M₁ may be equal to the total weight W_(total) of deposited material. When the amount of material M₂ delivered to paving machine 10 is provided as a volumetric value (e.g., in cubic meters, cubic yards, etc.), M₁ may be equal to the total volume V_(total) of deposited material. It is understood that M₁ may represent a different amount of material or have a different unit of measurement, if desired.

Controller 68 may also be configured to receive a third input indicative of the amount of material M₂ delivered to paving machine 10, and compare the amount of delivered material M₂ to the calculated amount of material M₁ deposited by paving machine 10 onto work surface 17. Controller 68 may be configured to receive the third input manually via input device 72 or automatically via communication device 66. The third signal may be indicative of a weight (e.g., a tonnage), a volume (e.g., a cubic yardage), or another unit of material that has been delivered to paving machine 10 and/or loaded into hopper 14. Controller 68 may receive the third signal each time material is delivered to paving machine 10. Controller 68 may be configured to compare the delivered amount of material M₂ to the calculated amount of material M₁ deposited onto work surface 17 in order to determine a correction factor Δ. For example, the correction factor Δ may be determined according to EQ2 below. Other ways of determining the correction factor Δ may be possible.

Δ=M ₂ /M ₁  EQ2:

The correction factor Δ may be indicative of a difference between the calculated amount of material M₁ deposited by paving machine 10 and the amount of material M₂ delivered to paving machine 10. The difference between M₁ and M₂ may be attributed to one or more production factors, depending on the circumstances. For example, material buildup in hopper 14 or conveyor system 18 and other known and/or unknown factors may contribute to the difference.

When the full amount of material M₂ delivered to paving machine 10 is deposited onto work surface 17, the amount of material M₂ delivered to paving machine 10 may be equal to an actual amount of material deposited onto work surface 17. Accordingly, controller 68 may be configured to determine the correction factor Δ each time the full amount of material delivered M₂ to paving machine 10 is deposited onto work surface 17. Controller 68 may be configured to multiply the correction factor Δ by future determinations of {dot over (V)}, {dot over (W)}, V_(total) and/or W_(total) in order to account for the difference between M₁ and M₂ and achieve more accurate determinations of the calculated amount of material M₁ deposited by paving machine 10.

INDUSTRIAL APPLICABILITY

The disclosed monitoring system may be applicable to any paving machine where tracking the instantaneous and/or total amount of deposited material is important. The monitoring system may allow for more accurate determinations of the instantaneous and/or total amount of deposited material based on material outflow from the conveyor, and may provide for automatic communication of paving material information between the paving machine and offboard entities. The monitoring system may also account for slippage between the paving material and the conveyor in order to improve the accuracy of the calculated instantaneous and/or total amount of deposited material. Operation of monitoring system 60 will now be explained.

Monitoring system 60 may help operators track paving production at one or more jobsites. Thus, at the beginning of a paving operation, the operator of paving machine 10 may select a saved profile associated with the current jobsite or create a new jobsite profile via interface device 62. The operator may select or create a jobsite identifier (e.g., a name, a number, etc.), and any machine settings or production statistics may be tracked and associated with the jobsite identifier. For example, monitoring system 60 may keep track of production data for each “pull” or each time paving machine 10 is set up to pave a portion of work surface 17, and store the data in association with the jobsite identifier for future reference and/or analysis.

Before each pull, controller 68 may receive one or more inputs of information regarding the paving material to be used during the paving process. For example, controller 68 may receive the first input indicative of the material efficiency factor γ from the operator via input device 72 or automatically via communication device 66. In one example, the operator may enter a value for the material efficiency factor γ via one or more buttons, a numeric key pad, soft keys, etc., associated with input device 72. Alternatively, controller 68 may receive the material efficiency factor γ automatically from communication device 66 when, for example, a signal indicative of the material efficiency factor γ is received from an offboard entity, such as a plant, a haul vehicle, or another entity. The material efficiency factor γ may be stored within the memory of controller 68 for further processing.

Controller 68 may also receive the second and third inputs indicative of the density ρ and the amount of material M₂ delivered to paving machine 10, respectively, before each pull. For example, the operator may enter the density ρ associated with the paving material and the amount of material M₂ (e.g., measured in tonnes, cubic meters, etc.) delivered by a particular truck via input device 72. In another embodiment, paving material information may be automatically received by controller 68 via communication device 66. For example, as a haul truck approaches paving machine 10 to deliver paving material, communication device 66 may automatically receive signals indicative of the density ρ, the amount M₂, and/or other information associated with the delivered paving material and communicate the signals to controller 68.

When the pull is started, the operator may indicate that screed assembly 16 is in a paving or “float” mode by, for example, pressing a button or soft key associated with input device 72. Conveyor 32 may begin to transfer material from hopper 14 to screed assembly 16, and controller 68 may track the conveying time t and store the conveying time t in its memory for future reference. When in float mode, paving machine 10 may be propelled in a forward direction by traction devices 22, and paving material may be deposited in front of screed assembly 16 by conveyor system 18. At this time, controller 68 may start to continually determine the amount of material M₁ being deposited by paving machine 10.

As paving machine 10 deposits material onto work surface 17, a flow of material may be traveling from hopper 14 to screed assembly 16 via tunnel 34. The fill level Φ of tunnel 34 may be detected by sensor 42, and a signal from sensor 42 indicative of the fill level Φ may be received by controller 68. The speed s₁ of conveyor 32 may be detected via sensor 44, and a signal from sensor 44 indicative of conveyor speed s₁ may be received by controller 68. Controller 68 may store the fill level Φ and conveyor speed s₁ in association with the current conveying time t within its memory for further processing.

Controller 68 may then calculate the amount of material M₁ deposited by paving machine 10 using EQ1. By multiplying s₁, γ, Φ, A_(T), and t together, controller 68 may determine the instantaneous volumetric rate of material deposition {dot over (V)} onto work surface 17. By multiplying the instantaneous volumetric rate of material deposition {dot over (V)} by the paving time t, controller 68 may then determine the volume V of material deposited onto work surface 17. By summing the volume V of deposited material over a period of time (e.g., a shift, a day, for time spent on a particular jobsite, etc.), controller 68 may determine the total volume V_(total) of deposited material. Controller 68 may then show the instantaneous volumetric rate of material deposition {dot over (V)} and/or the total volume V_(total) of deposited material to the operator of paving machine 10 via display 70.

Controller 68 may then multiply the instantaneous volumetric rate of material deposition {dot over (V)} and/or the total volume V_(total) of deposited material by the density ρ of the material delivered to paving machine 10 to determine the instantaneous rate of material deposition by weight {dot over (W)} and/or a total weight W_(total) of deposited material, respectively. Controller 68 may then show the instantaneous rate of material deposition by weight {dot over (W)} (e.g., tonnes/hour) and/or the total weight W_(total) (e.g., tonnes) of deposited material to the operator of paving machine 10 via display 70. Accordingly, M₁ may be equal to the total volume V_(total) or the total weight W_(total), as desired (e.g., depending on whether density was an input in EQ1), and controller 68 may store M₁ within its memory for further processing.

After the full amount of material M₂ delivered to paving machine 10 has been moved from hopper 14 by conveyor system 18 and deposited onto work surface 17 under screed assembly 16, controller 68 may then determine the correction factor Δ based on the amount of material M₂ delivered and the calculated amount of material M₁ deposited by paving machine 10. For example, when the operator of paving machine 10 determines that the full amount M₂ of material delivered to paving machine 10 has been deposited onto work surface 17, the operator may press a button or soft key associated with input device 72 causing controller 68 to calculate the correction factor Δ (e.g., using EQ2). Controller 68 may then show the correction factor Δ to the operator via display 70.

To refill hopper 14, a subsequent amount M₂ of material may then be delivered to paving machine 10 via a haul truck or other source. The subsequent amount M₂, the corresponding density ρ, and the corresponding material efficiency factor γ of the delivered material may be manually entered by the operator (e.g., via input device 72) or automatically received via communication device 66. In this way, the correction factor Δ may be determined each time paving machine 10 receives more material.

In some situations, however, deliveries may be made to paving machine 10 that are not immediately entered into controller 68 either manually or automatically. In these situations, the operator may subsequently enter each previous delivery at a convenient time via input device 72, and controller 68 may update the correction factor Δ at that time based on the delivered amounts and the calculated total volume V_(total) and/or total weight W_(total) since the last logged delivery. Alternatively, the operator may enter a total amount of material delivered during a number of deliveries as well as a number trucks used to deliver the material, and controller 68 may determine an average delivery amount before updating the correction factor Δ.

After hopper 14 is refilled with a subsequent amount M₂ of material delivered to paving machine 10 and a subsequent pull is initiated, controller 68 may multiply subsequent determinations of {dot over (V)}, {dot over (W)}, V_(total) and/or W_(total) by the correction factor Δ before showing them to the operator via display 70. In this way, the determinations of {dot over (V)}, {dot over (W)}, V_(total) and/or W_(total) may be more accurate as the paving process continues, allowing operators to quickly identify and adjust paving parameters that are outside desired specifications based on the corrected determinations. By showing operators the correction factor Δ, operators may also be able to determine how accurate the calculated determinations are over a given amount of paving time.

Several advantages may be associated with the disclosed monitoring system. For example, because controller 68 may receive and store paving material information, statistical tabulations and calculations may be performed automatically by controller 68, allowing operators to focus on other aspects of the paving operation. Also, because the material efficiency factor γ may be received by controller 68, the amount of material deposited by paving machine 10 may be more accurately determined with readily available information, thereby requiring less sensory equipment. Further, because controller 68 may determine the correction factor Δ based on material delivery information received and other material information calculated during the paving process, subsequent calculations of the rate and amount of material deposited onto work surface 17 may be more accurate, allowing operators to more accurately identify when and how to adjust paving parameters to satisfy customer specifications.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed monitoring system. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed monitoring system. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents. 

What is claimed is:
 1. A monitoring system for a paving machine having a conveyor system configured to convey paving material, the monitoring system comprising: an input device configured to receive a first input indicative of a paving material efficiency factor; a first sensor configured to generate a first signal indicative of a conveyor speed; and a controller electronically connected to the input device and the first sensor and configured to determine an amount of material deposited by the paving machine based on the paving material efficiency factor and the conveyor speed.
 2. The monitoring system of claim 1, wherein: the conveyor system includes a tunnel; the monitoring system further includes a second sensor in electronic communication with the controller and configured to generate a second signal indicative of a fill level of the tunnel; and wherein the controller is configured to determine the amount of material deposited by the paving machine based on the fill level of the tunnel.
 3. The monitoring system of claim 2, wherein the controller is configured to: determine a material area based on the fill level of the tunnel and an area of the tunnel; and determine the amount of material deposited by the paving machine based on the material area.
 4. The monitoring system of claim 3, wherein the controller is further configured to: receive a second input indicative of a material density via the input device; and determine the amount of material deposited by the paving machine based on the material density.
 5. The monitoring system of claim 4, wherein the controller is configured to: receive a third input indicative of an amount of a material delivered to the paving machine via the input device; and determine a correction factor based on the amount of the material deposited by the paving machine and the amount of material delivered to the paving machine.
 6. The monitoring system of claim 5, wherein the controller is further configured to determine a subsequent amount of material deposited by the paving machine based on the correction factor.
 7. The monitoring system of claim 5, wherein the controller is further configured to determine a rate of material deposition based on the correction factor.
 8. The monitoring system of claim 7, further including a display in electronic communication with the controller, wherein the controller is configured to show one or more of the amount of material deposited, the rate of material deposition, and the correction factor to an operator of the paving machine via the display.
 9. The monitoring system of claim 5, wherein the input device is an operator interface configured to receive one or more of the first, second, and third inputs from an operator of the paving machine.
 10. The monitoring system of claim 5, wherein the input device is a communication device configured to automatically receive one or more of the first, second, and third inputs from offboard the paving machine.
 11. A method of monitoring a paving machine having a conveyor system, the method comprising: conveying paving material through a tunnel associated with the conveyor system; receiving a first input indicative of a paving material efficiency factor; receiving a first signal indicative of a conveyor speed; and determining an amount of material deposited by the paving machine based on the paving material efficiency factor and the conveyor speed.
 12. The method of claim 11, wherein: the method further includes receiving a second signal indicative of a fill level of the tunnel associated with the conveyor system; and the amount of material deposited by the paving machine is determined based on the fill level of the tunnel.
 13. The method of claim 12, wherein: the method further includes determining a material area based on the fill level of the tunnel and an area of the tunnel; and the amount of material deposited by the paving machine is determined based on the material area.
 14. The method of claim 13, wherein: the method further includes receiving a second input indicative of a material density; and determining the amount of material deposited by the paving machine based on the material density.
 15. The method of claim 14, further including: receiving a third input indicative of an amount of a material delivered to the paving machine; and determining a correction factor based on the amount of the material deposited by the paving machine and the amount of material delivered to the paving machine.
 16. The method of claim 15, further including determining a subsequent amount of material deposited by the paving machine based on the correction factor.
 17. The method of claim 15, further including determining a rate of material deposition based on the correction factor.
 18. The method of claim 17, further including showing one or more of the amount of material deposited, the rate of material deposition, and the correction factor to an operator of the paving machine via a display.
 19. The method of claim 15, wherein one or more of the first, second, and third inputs are received via at least one of an operator interface and a communication device configured to automatically receive the one or more of the first, second, and third inputs from offboard the paving machine.
 20. A paving machine comprising: a machine frame; a plurality of traction devices configured to support the machine frame; an engine mounted to the machine frame and configured to drive the plurality of traction devices; a hopper mounted at a first end of the machine frame; a conveyor system configured to transport material from the hopper to a second end of the machine frame via a tunnel associated with the conveyor system; and a screed mounted at the second end of the machine frame; and a monitoring system associated with the conveyor system and including: an input device configured to receive a first input indicative of a paving material efficiency factor; a first sensor configured to generate a first signal indicative of a conveyor speed; a second sensor configured to generate a second signal indicative of a fill level of the tunnel; and a controller electronically connected to the input device and the first and second sensors and configured to determine an amount of material deposited by the paving machine based on the paving material efficiency factor, the conveyor speed, and the fill level of the tunnel. 